package Tree;

/**
 * @BelongsProject: SeniorArchitect-LeetCode
 * @BelongsPackage: Tree
 * @Author: zhuangxiaoyan
 * @CreateTime: 2023-10-31  23:12
 * @Description: TODO
 * @Version: 1.0
 */
public class 二叉树左下角的值513 {

    public class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;

        TreeNode() {
        }

        TreeNode(int val) {
            this.val = val;
        }

        TreeNode(int val, TreeNode left, TreeNode right) {
            this.val = val;
            this.left = left;
            this.right = right;
        }
    }

    int maxDepth = Integer.MIN_VALUE;
    int result;

    public int findBottomLeftValue(TreeNode root) {
        if (root == null) {
            return 0;
        }
        travel(root, 1);
        return result;
    }

    public void travel(TreeNode root, int depth) {
        // 遍历到叶子节就停止
        if (root.left == null && root.right == null) {
            if (depth > maxDepth) {
                maxDepth = depth;
                result = root.val;
            }
        }
        if (root.left != null) {
            depth++;
            travel(root.left, depth);
            depth--;
        }
        if (root.right != null) {
            depth++;
            travel(root.right, depth);
            depth--;
        }
    }
}
